| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.crypto.random; |
| |
| import java.util.Random; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.util.NativeCodeLoader; |
| |
| import com.google.common.base.Preconditions; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * OpenSSL secure random using JNI. |
| * This implementation is thread-safe. |
| * <p/> |
| * |
| * If using an Intel chipset with RDRAND, the high-performance hardware |
| * random number generator will be used and it's much faster than |
| * {@link java.security.SecureRandom}. If RDRAND is unavailable, default |
| * OpenSSL secure random generator will be used. It's still faster |
| * and can generate strong random bytes. |
| * <p/> |
| * @see https://wiki.openssl.org/index.php/Random_Numbers |
| * @see http://en.wikipedia.org/wiki/RdRand |
| */ |
| @InterfaceAudience.Private |
| public class OpensslSecureRandom extends Random { |
| private static final long serialVersionUID = -7828193502768789584L; |
| private static final Logger LOG = |
| LoggerFactory.getLogger(OpensslSecureRandom.class.getName()); |
| |
| /** If native SecureRandom unavailable, use java SecureRandom */ |
| private java.security.SecureRandom fallback = null; |
| private static boolean nativeEnabled = false; |
| static { |
| if (NativeCodeLoader.isNativeCodeLoaded() && |
| NativeCodeLoader.buildSupportsOpenssl()) { |
| try { |
| initSR(); |
| nativeEnabled = true; |
| } catch (Throwable t) { |
| LOG.error("Failed to load Openssl SecureRandom", t); |
| } |
| } |
| } |
| |
| public static boolean isNativeCodeLoaded() { |
| return nativeEnabled; |
| } |
| |
| public OpensslSecureRandom() { |
| if (!nativeEnabled) { |
| fallback = new java.security.SecureRandom(); |
| } |
| } |
| |
| /** |
| * Generates a user-specified number of random bytes. |
| * It's thread-safe. |
| * |
| * @param bytes the array to be filled in with random bytes. |
| */ |
| @Override |
| public void nextBytes(byte[] bytes) { |
| if (!nativeEnabled || !nextRandBytes(bytes)) { |
| fallback.nextBytes(bytes); |
| } |
| } |
| |
| @Override |
| public void setSeed(long seed) { |
| // Self-seeding. |
| } |
| |
| /** |
| * Generates an integer containing the user-specified number of |
| * random bits (right justified, with leading zeros). |
| * |
| * @param numBits number of random bits to be generated, where |
| * 0 <= <code>numBits</code> <= 32. |
| * |
| * @return int an <code>int</code> containing the user-specified number |
| * of random bits (right justified, with leading zeros). |
| */ |
| @Override |
| final protected int next(int numBits) { |
| Preconditions.checkArgument(numBits >= 0 && numBits <= 32); |
| int numBytes = (numBits + 7) / 8; |
| byte b[] = new byte[numBytes]; |
| int next = 0; |
| |
| nextBytes(b); |
| for (int i = 0; i < numBytes; i++) { |
| next = (next << 8) + (b[i] & 0xFF); |
| } |
| |
| return next >>> (numBytes * 8 - numBits); |
| } |
| |
| private native static void initSR(); |
| private native boolean nextRandBytes(byte[] bytes); |
| } |